Question

1. what (and why) does a step-up transformer do?

decrease voltage to make it safe for homes

decrease voltage to make it more powerful

increase voltage so that the electricity can travel longer distances (from the power plant to the houses)

increase voltage so you can use more electricity in your home at the same time

Explanation:

A step - up transformer increases voltage. When electricity is transmitted over long distances (from power plants to houses), increasing the voltage reduces power loss (since \(P = I^{2}R\) and \(P=VI\), increasing \(V\) decreases \(I\) for the same power, thus reducing \(I^{2}R\) loss). The first option is for a step - down transformer (used to make voltage safe for homes). The second option is incorrect as decreasing voltage doesn't make it more powerful. The fourth option is wrong because home appliances need specific (lower) voltages, and a step - up transformer isn't for home usage to increase electricity usage. The third option correctly states that a step - up transformer increases voltage to allow electricity to travel longer distances with less loss.

Answer:

C. increase voltage so that the electricity can travel longer distances (from the power plant to the houses)